Climate-Driven Variability and Trends in Mountain Snowpack in Western North America

by

Philip Mote

,

American Meteorological Society

Examines records of April 1 snow water equivalent (SWE) using multiple linear regression against reference time series of temperature and precipitation

States that this method permits 1) an examination of the separate roles of temperature and precipitation in determining the trends in SWE; 2) an estimation of the sensitivity of SWE to warming trends, and its distribution across western North America and as a function of elevation; and 3) inferences about responses of SWE to future warming

Results emphasize the sensitivity to warming of the mountains of northern California and the Cascades of Oregon and Washington

Examines the contribution of modes of Pacific climate variability and finds these to be responsible for about 10%–60% of the trends in SWE, depending on the period of record and climate index